An Optimized Algorithm for Sf6 Leakage Detection

Sulphur hexafluoride (SF6) is an inert and non-toxic gas with excellent properties for arc quenching and electrical insulation applications. The main drawback is its high greenhouse potential. In high voltage apparatuses it is used in sealed volumes e.g. in the interrupting chamber of a circuit breaker. Even so, through flanges and o-rings we encounter always a small amount of gas leakage. Therefore monitoring the leakage rate becomes an inevitable duty. Unfortunately the detection of small gas leakages in SF6 switchgear is not an easy task due to thermally originated fluctuations in the pressure or density signals. For ISH 2007 we presented a new theoretical approach to detect small gas leakages in SF6 switchgear. In the meanwhile this approach has been modified which lead to a significant reduction of necessary computational power and therefore allows to handle the necessary calculation by a standard personal computer. At the same time the accuracy of the model has been increased to 0.3%.